ANATEXIS AND GRANITIZATION: CRITERIA AND MODELS

Year, pages: 1991, 45 - 52

The models of anatexis and granitization (very popular in the Soviet literature) are compared, based on experimental, mineralogical, geochemical, structural geological data. The melt indusion and mineralogical data coupled with field geological observations are good evidence that the origin of most of migmatites, charnockites and gneiss-granites is the result of crystallization of acidic melt saturated by H₂0 and CO₂ at the temperature 650–900 °C. Three possible variants of the process of formation of these acidic melts may be considered: a) pure anatexis; b) partial melting with some additional mantle-derived fluids; c) granitization as magmatic substitution with intensive fluid infiltration. The model of anatexis is the most likely as the simpliest one and it is based on geological, mineralogical and melt inclusion data (Bowen, Tuttle, Winkler, Brown, Fyfe, Sobolev, etc.). The evidence put forward for alternative models (Zharikov 1987, etc.) may be explained in the framework of the anatectic model or are very ambiguous in reality. The geological and petrological data on some typical areas (Baikal region, Aldan shield, Pamir block, the South India) were compared from these points of view. The CO₂-rich fluid flow typical of granulite complexes is possible from the "hot" mantle. The source of H₂0 for melting in the lower crust may be the biotite of the rocks or filtrating and crystallization of specific mantle magma enriched in H₂O (Litvinovsky & Podladchikov 1990).

L. Dobretsov, N., A. Shafeev, A. 1991. ANATEXIS AND GRANITIZATION: CRITERIA AND MODELS. In Geologica Carpathica, vol. 42, no.1, pp. 45-52. 1335-0552.

L. Dobretsov, N., A. Shafeev, A. (1991). ANATEXIS AND GRANITIZATION: CRITERIA AND MODELS. Geologica Carpathica, 42(1), 45-52. 1335-0552.